Flow Field Analysis of a Diverterless Supersonic Inlet using Embedded LES Methodology

The understanding of the flow field in the vicinity of fuselage/air inlet integration area and inside air intake is important for performance estimation of an air intakepropulsion system combination. In this paper flow field simulation of a Diverterless Supersonic Inlet (DSI) is carried out using Embedded LES (ELES) methodology. Zonal embedded mesh strategy is devised to resolve the integral length scale in LES zone. The analysis is carried out at a subsonic Mach number M _∞ =8 and a supersonic M _ach number M _∞ =1.53. For each Mach number analysis is initially carried out at a design mass flow rate condition, flow field variations are subsequently analyzed for low and high mass flow rate conditions. Flow field is analyzed to ascertain the quality of flow exiting the air intake duct and entering engine. The existence of turbulent vortical structures formed inside duct due to wall shear effects is observed. The duct curvature adds an inherent swirl to the flow. Secondary flow structure at engine face plane remains relatively uniform at low and design mass flow rates for both subsonic and supersonic conditions. At high mass flow rate condition the secondary flow structure loses its uniformity with an increase in swirl magnitude. The shockwave structure on the bump compression surface is also effectively captured using the ELES methodology. The subsonic and supersonic total pressure recovery characteristic computed using ELES methodology showed agreement when compared with wind tunnel data.